How many histories can I use on a Jace8000?

How many individual history logs and how much data I can store on a Jace8000 depend on a few factors

The Jace8000 is quite a powerful device. Compared to older series such as the most powerful AX controller Jace600, the CPU, RAM and FLASH memory have vastly improved. This translates also in much greater capabilities when it comes to store history logs locally.

But the question is: what are the limits of the Jace8000 when it comes to store logs?

 

Interestingly enough, this topic is explained on the Niagara TCP Advanced certification, but it is quite important for any development.

Following the instructions from Tridium, the recommended maximum amount of Histories for a Jace8000 with 1000MB of RAM and Niagara4 is 6400. That is referring to individual different histories, not the amount of data you log on each individual history or in total.

To put that in perspective, a Jace600 with 256MB of RAM running Niagara 3.8.38 has 1600 recommended maximum amount of Histories.

 

The next question then would be: how many logs can I have in total then?

To get this answer we need to open the platform of our Jace8000. From there, we will need to open the Platform administration, where we can find the "Configure NRE Memory" section:

 

Clicking that, you get to the NRE memory settings

 

The window provides a few information about how memory is used. We can clearly see that our history data is stored in the RAM disk. We can also see that the RAM disk by default is about 384MB. Note this could change slightly with different Niagara 4 versions, so please check the specific setting on your controller.

Removing the space used for alarm logs and the audit histories, you will have about 360MB available for the data histories.

Each log event will use a certain amount of bytes based on the data being logged. We would suggest to use the Excel sheet available on our support website HERE to get an idea on the space your logs would require in MB.

 

Side note: remember that if you plan to synchronize your internal history logs with a third party database (ie SQL) using the RDBMS driver, the driver is only supported by the supervisor, not the Jace or any other Niagara controller. Because of the extended capabilities of the Jace8000 it might be tempting, but it is not possible unfortunately.